1. Field of the Invention
This invention relates generally to medical electrode systems. In particular, the electrodes of this invention are capable of universal application to patient""s of any size. The electrodes of this invention are appropriate for use with defibrillators, including an automatic or semi-automatic external defibrillator (xe2x80x9cAEDxe2x80x9d) and defibrillators capable of cardioversion or external pacing.
2. Description of the Prior Art
Cardiac arrhythmias treatable with an electric shock can be further categorized as arrhythmias treated by a defibrillation energy shock or arrhythmias treated by a synchronized cardioversion energy shock. Electric shocks are typically delivered by defibrillators or cardioverters. Many devices capable of delivering a defibrillation shock are also capable of delivering synchronized cardioversion shocks. Defibrillation is typically used to treat ventricular fibrillation (xe2x80x9cVFxe2x80x9d) and pulseless ventricular tachycardia (xe2x80x9cVTxe2x80x9d), while cardioversion is typically used to treat hemodynamically stable ventricular tachycardia (xe2x80x9cVT with pulsexe2x80x9d), paroxysmal supraventricular tachycardia (xe2x80x9cPSVTxe2x80x9d), atrial fibrillation (xe2x80x9cAFxe2x80x9d) and atrial flutter. More detailed information about electrocardiography and the various types of heart rhythms may be obtained from Wagner xe2x80x9cMarriott""s Practical Electrocardiography,xe2x80x9d 9th Ed. (1994).
One frequent consequence of heart attacks is the development of cardiac arrest associated with heart arrhythmias, such as VF. This abnormal heart rhythm is caused by an abnormal and chaotic electrical activity in the heart. During VF the heart cannot pump blood effectively. VF is treated by applying a defibrillation shock to the patient""s heart through the use of a defibrillator. Defibrillation clears the heart of the abnormal electrical activity and allows the heart""s natural pacemaker areas to restore normal function. Because blood is no longer pumping effectively during VF, the chance of surviving sudden cardiac arrest decreases with time. Quick response to sudden cardiac arrest by administering a defibrillating shock as soon as possible after the onset of VF is therefore often critically important.
VT is an arrhythmia originating in the ventricles, and is usually defined as having a heart rate of  greater than 100 beats/minute in an adult. VT can result in a significant health risk, since the ability of the heart to pump adequate blood is compromised. As a result, blood pressure falls. Hemodynamically stable VT is typically treated using synchronized energy pulses known as cardioversion that are delivered in a standard sequence of, for example, 100, 200, 300 and 360 J. Although in some situations, pulses may begin with as little as 50 J. Hemodynamically unstable VT is typically treated with unsynchronized shocks. The most current protocol information can be obtained from the American Heart Association (xe2x80x9cAHAxe2x80x9d). The protocol information described herein can be found in xe2x80x9cImproving Survival from Sudden Cardiac Arrest: The xe2x80x98Chain of Survivalxe2x80x99 Conceptxe2x80x9d Circulation 83:1832-1847 (1991).
Increasing the number of potential defibrillator operators who are trained in the proper use of an external defibrillator increases the likelihood that a trained defibrillator operator will be available during an emergency and thus could ultimately reduce the time to defibrillator deployment. As the number of potential operators increases, however, it becomes increasingly important to ensure that defibrillator electrode pads of an appropriate size are available to treat the patient.
What is needed is an electrode system that is easily adaptable to the size of the patient.
This invention describes an electrode system that is easily adaptable to the size of the patient. This invention also describes methods of manufacture of an electrode system and methods of use.
This invention describes a disposable medical electrode pad comprising: a conductive gel layer having two surfaces each with a surface area; a single, separable conductive layer with a first conductive electrode section or area having two surfaces each with a surface area wherein one surface of the conductive electrode layer is adhered to one surface of the conductive gel layer and wherein the surface area of the first conductive layer is less than 100 cm2; a second conductive electrode layer having two surfaces each with a surface area wherein one surface of the conductive electrode layer is adhered to one surface of the conductive gel layer and wherein the surface area of the second conductive layer is less than 150 cm2; conductors in communication with the first and second conductive electrode layers wherein the conductors selectively deliver therapy through the first or second conductive electrode layer; and a dielectric layer. The surface area of the first conductive layer may be less than 75 cm2 or 50 cm2. Additionally, the surface area of the second conductive electrode layer may be less than 100 cm2 or 75 cm2. A third conductive electrode layer may also be provided in communication with the first and second conductive electrode layers. When a third conductive layer is provided, it ideally has a surface area of less than 40 cm2. Any of these electrode pads are capable of delivering pulses of electrical energy, such as defibrillation pulses, cardioversion pulses, or pacing pulses. As configured, the first conductive electrode element is removable from the second electrode element and, when applicable, the third conductive element is removable from the first and second electrode elements. The gel layer may be contiguous, separated into first and second gel sections, or fairly contiguous with one or more sets of perforations along a length. The foam backing can similarly be contiguous, comprised of multiple sections or feature one or more sets of perforations along its length. A release liner may also be attached to one side of the gel layer. The release liner may be contiguous, comprised of multiple sections, or feature one or more sets of perforations along its length.
Alternatively, the disposable medical electrode pad may comprise: a first conductive gel layer having two surfaces each with a surface area; a second conductive gel layer having two surfaces each with a surface area; a conductive electrode layer having two surfaces each with a surface area wherein one surface of the conductive electrode layer is adhered to one surface of the conductive gel layer and wherein the surface area of the first conductive layer is less than 150 cm2; conductors in communication with the conductive electrode layer; and a dielectric layer. In this embodiment, the conductive electrode layer may further comprise a first conductive electrode layer and a second conductive electrode layer. The surface area of the first conductive electrode layer is less than 75 cm2 or 50 cm2. The surface area of the second conductive electrode layer is less than 100 cm2 or 75 cm2. Additionally, a third conductive electrode layer in communication with the first and second conductive electrode layers. Where a third conductive layer is provided, its surface area is less than 40 cm2. These electrode pads are also capable of delivering pulses of electrical energy, such as defibrillation, cardioversion or pacing. In this construction, the first conductive electrode element is removable from the second electrode element and, when applicable, the third conductive electrode element is removable from the first and second electrode element. The dielectric layer can be formed from a first dielectric layer and a second dielectric layer or the dielectric layer may be perforated along its length. A release liner may also be attached to one side of the gel layer. The release liner may be contiguous, comprised of multiple sections, or feature one or more sets of perforations along its length.
In another alternative, the disposable medical electrode pad comprises: a conductive gel layer; a conductive electrode layer having two surfaces each with a surface area wherein one surface of the conductive electrode layer is adhered to one surface of the conductive gel layer and wherein the surface area of the first conductive layer is less than 150 cm2; conductors in communication with the conductive electrode layer; a first dielectric layer; and a second dielectric layer. The conductive electrode layer may further comprise a first conductive electrode layer and a second conductive electrode layer. In that case, the surface area of the first conductive electrode layer may be less than 75 cm2 or more preferably less than 50 cm2; and the second conductive layer is less than 100 cm2 or more preferably less than 75 cm2. As with the previous embodiments, a third conductive electrode layer in communication with the first and second conductive electrode layers. In that case, the surface area of the third conductive electrode layer is less than 40 cm2. These electrode pads are suitable for delivering pulses of electrical energy. These pulses include, defibrillation, cardioversion and pacing. In this construction, the first conductive electrode element is removable from the second electrode element and, when applicable, the third conductive electrode element is removable from the first and second electrode element. The gel layer may be contiguous, formed from a first gel layer and a second gel layer, or may be perforated along its length. A release liner may also be attached to one side of the gel layer. The release liner may be contiguous, comprised of multiple sections, or feature one or more sets of perforations along its length.
The invention also contemplates a method of using a disposable medical electrode pad comprising: determining the physiological size of a patient; determining whether to remove a portion of a conductive electrode layer from an electrode pad prior to applying the electrode pad to the patient; applying the electrode pad to the patient; and monitoring the patient""s condition. Further, the step of: removing a portion of the conductive electrode layer from the electrode pad may also be performed where an electrode with a smaller surface area is desired. In operation, this method of using the electrode enables the device to deliver defibrillation, cardioversion or pacing pulses.
The invention also includes methods of manufacturing the electrodes. In one method of manufacture, the steps of: cutting a layer of conductive gel to a desired shape; cutting a layer of conductive element to a desired shape; carefully registering the conductive gel layer and the conductive electrode layer; connecting a wire to the conductive electrode layer; and adhering the registered gel and conductive element to each of a plurality of dielectric layers.
In another method of manufacturing, the electrodes are made by: cutting a layer of conductive gel into a plurality of desired shapes; cutting a layer of conductive element to a desired shape; carefully registering the conductive gel layers and the conductive electrode layer; connecting a wire to the conductive electrode layer; and adhering the registered gel and conductive element to a dielectric layers.
In yet another method of manufacturing, the electrodes are made by: cutting a layer of conductive gel to a desired shape; cutting a layer of conductive element into plurality of desired shapes; carefully registering the conductive gel layer and the conductive elements; connecting wires to the conductive electrode layers; and adhering the registered gel and conductive element to one or more dielectric layers.